This walk is a dramatic traverse of the Black Mountains and the Breacon Beacons National Park. It is not waymarked, but is clearly marked on Ordnance Survey maps.

The walk starts just outside Abergavenny (train station, pubs, shops, etc.) on the B4521, and ascends Ysgyrwd Fawr (486m), then back down to the valley to Llanvihangel (pub, near Pandy train station). Then the start of a great Black Mountain ridge walk over Hatterrat Hill (531m), before descending to Llanthony (pub).

The next stage is a traverse of the southern edge of the Black Mountains past Crug Mawr (550m) to Crickhowell (classic pub, shops, camp site). Another option is to contineu on to Cwmdu (camp site, pub). Then its over Cefn Moel (approx 412 m) to Bwlch (pub, shop) and Llangynidr (pub, last shop on the walk!)

The next stage is a big one, along the remote Talybont Reservoir, then part of the classic Beacons horseshoe ridge walk, passing Fan Y Big (719m) and the highest peak in the National Park, Pen Y Fan (886 m). Amazing views on a clear day, but dangerous in bad weather with indistinct paths, and steep drops. You descend to the Storey Arms (no longer a pub, no facilities, just a car park by an A road)

Next is a long traverse of the very remote Fforest Fawr - moorland, no facilities, crossing only 1 minor road until you get to Glyntawe by the Dan-yr-Ogof caves tourist attraction (pub, camp site)

Next is the Black Mountain, Fan Brycheiniog (802), at the end of long clacial ridge with a very steep drop on 1 side. Great views over Gower and the Bristol Channel on clear day. Down to the valley at Llanddeusant (camp site)

Back up to the tops for a traverse of the remote Black mountains to Carreg Cennen Castle and before heading north to Bethlehem, a hamlet on the park boundary. Its a few miles more to Llangadog (pub, train station)

Logistically, the walk is very difficult. There are few shops and little public transport, and none at all in the central and western half of the walk of the walk. The central stretch cannot be done without camping (or a support car/significant detour to overnight accommodation)